The present invention relates generally to a seatbelt apparatus mounted to a vehicle and, more specifically, to the detection of whether or not a seatbelt is worn and an improved technique for guiding the fastening of the seatbelt.
A vehicle, such as a motor vehicle, is provided with a seatbelt apparatus for protecting a passenger in case of a vehicle collision. The seatbelt apparatus may include a seatbelt and a spool for feeding and retracting the seatbelt.
In the related art, it is detected whether or not the seatbelt is worn and various controls are performed on the basis of a detected signal indicating whether or not the seatbelt is worn. For example, the seatbelt apparatus may include a motor for driving a spool. The motor is controlled to perform the retraction or feeding of the seatbelt on the basis of the signals indicating whether or not the seatbelt is worn.
A seatbelt apparatus may be provided with a buckle switch which detects a tongue on a seatbelt that is inserted into a buckle or that is pulled out from the buckle, thus detecting whether or not the seatbelt is in a worn state. When a detection signal indicating that the tongue is inserted into the buckle is outputted, a motor is driven in the direction of retracting the seatbelt for eliminating the slack in the seatbelt. When a detection signal indicating that the tongue is pulled out from the buckle is outputted from the buckle switch, the motor is driven in the direction of retracting the seatbelt in order to store the seatbelt.
According to another proposed embodiment, a seatbelt apparatus is provided with an illumination lamp, which illuminates the buckle so that the passenger can wear the seatbelt easily. In this embodiment, the illumination lamp for illuminating the buckle of the seatbelt apparatus is installed in a console box provided on the floor of the cabin at the center. When the passenger opens a vehicle door to enter the vehicle, a detection signal indicating that the vehicle door is opened is supplied to an illumination control unit. Accordingly, the illumination control unit illuminates the illumination lamp. Subsequently, when the passenger inserts the tongue into the buckle, a detection signal indicating that the tongue is inserted into the buckle is supplied to the illumination control unit. Accordingly, the illumination control unit turns the illumination lamp off.
In the seatbelt apparatus shown in Japanese Unexamined Patent Application Publication No. 2004-237827, it is necessary to provide a signal line for outputting a detection signal indicating whether or not the tongue is inserted into the buckle to the illumination control unit and to separately provide a power cable for supplying power to the illumination lamp. In other words, it is necessary to provide a wire harness for the detection signals and a wire harness for the power between the seat (buckle) on which the seatbelt is installed and the illumination control unit.
In vehicles such as a motor vehicle or an airplane, the reduction of the number of wire harnesses is required for reducing the working load and for reducing the cost. In view of such a point, there is a need to provide a technique for effectively reducing the number of the wire harnesses required for detecting whether the seatbelt is worn or not worn and for supplying power to a light-emitting apparatus.
It is to be understood that both the foregoing general description and the following detailed descriptions are exemplary and explanatory only, and are not restrictive of the invention as claimed.